What does resistance oppose in an electrical circuit?

Resistance in an electrical circuit specifically opposes the flow of electrons. When a voltage is applied across a conductor, it creates an electric field that pushes electrons through the material. However, resistance acts as a hindrance to this flow. The higher the resistance, the more difficult it becomes for electrons to pass through, which in turn limits the amount of current that can flow for a given voltage.

This concept is fundamental to Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). Thus, as resistance increases, the current decreases, assuming voltage remains constant. Understanding resistance's role as a barrier to electron flow is crucial for analyzing and designing electrical circuits, as it directly impacts how efficiently electrical energy can be transmitted and used.

The other options relate to different aspects of electrical circuits but don't accurately capture what resistance acts upon. Voltage refers to the potential difference that drives electron flow, power represents the rate of energy transfer, and frequency pertains to the rate at which alternating current changes direction. None of these concepts directly characterize the primary function of resistance, which is to impede the movement of electrons.